I have recently migrated from SPSS to Stata to allow me to implement
fractional polynomial techniques, including the mfp procure, for a
logistic regression analysis. I have been able to save the original
SPSS file in Stata format. The variables in the SPSS file were of
numeric "Type" (in the sense intended by the SPSS Variable View
facility) with text labels linked to the numerical codes using the
SPSS Value Labels function. On opening up the Stata version of this
file, the text labels appear in the individual columns for the
dependent and independent variables. When I run the code for
identifying the Stata file and running the mfp procedure, the error
code r(2000) is generated, pointed to an absence of observations.

Is it possible that I require to reformat the data in some way for
the procedure to run successfully? I would be grateful for some
handy tips to save some time.

If you have access to it (or are willing to buy it) I would trust
Stat/Transfer more than I would SPSS's own conversion utility. You
might also try -usespss-, which can be downloaded for free from SSC.